Grand Ayatullah Sayyid Ali Husaini Sistani was born on 9th Rabi Al-Awwal 1349 A.H. in the holy city of Mashhad. He was named Ali after his grandfather.
He was brought up into a family known for its religious background. He learned theological and rational sciences from many eminent and well-known religious scholars.

His father was named Sayyid Muhammad Baqir and his grandfather was the great ‘Sayyid Ali’ whose detailed biography has been brought in the book ‘Tabaqaat Al-a’laam Al-Shi`a (Categories of Shia Scholars) (part 4 page 1432) by Aqa Buzurg Tehrani. He has mentioned that he was apprenticed to Late Ali Nahavandi in Najaf and to Mujadded Shirazi in Samarra ,iraq and finally to Sayyid Isma`il Sadr. In 1308 A.H. he returned to Mashhad and therein he settled and gained reputation as the teacher of renowned scholars such as the great Jurisprudent, Mohammad Reza Aal Yasin (may Allah bless him).
In 1368 A.H. during the period of the Great Jurisprudent, Grand Ayatullah Sayyid Hussayn Burujirdi he shifted to the holy city of Qum where he attended Kharij lectures of Fiqh and Usul (Jurisprudence & Fundamentals of Jurisprudence) given by prominent scholars of the Religious Seminary including Ayatullah Burujirdi (may Allah bless him). He also attended Fiqh lectures of Grand Sayyid Kohkamari during whose time he achieved much erudity and experience in Fiqh as well in Rijal and Hadith sciences.

His wife and children lived in Isfahan during the Safavid period and his great grandfather Sayyid Mohammad, appointed as Shaikhul Islam by King Hussain of the Safavid dynasty in Sistan province. Later he traveled to Sistan where he and his children remained settled.
Sayyid Ali was the first of his grandsons to migrate to Mashhad. He lived in the Madresa of late Mohammad Baqir Sabsavari where he continued studying until he migrated to the holy city of Najaf for higher studies.

At the age of 5 His Eminence started learning the Holy Quran. A woman who was known as ‘Mother of Aqaye Mudir’ helped him learnt the Quran. He was then admitted in a religious center for reading, writing, and for learning basic mathematics and geography. He graduated from the center after he had learnt calligraphy from Mirza Ali Aqa Zalim.

In the beginning of 1360 he started studying basic Hawzah lessons. He finished reading a number of books namely, Sharh Alfyyah by Soyuti, Moghni by Ibn-e Hisham, Motawwal by Taftazani, Maqamaat Al-Tabriri and Sharh Al-Nizam. Of those who taught him at this level one was Nishabouri who was known as a man of letters. He studied Sharh Lum’ah and the book of Qawanin (Laws) with late Sayyid Ahmad Yazdi known as Nahang. He finished the Sath (level before Kharij Level) books such as Makasib, Rasa’il and Kifayah with Shaykh Hashim who was one of the great scholars of his time. He also read a number of books on philosophy like Sharh Manzuma-e Sabsavari and Sharh Ishraq and Asfar of Sadrul Mutaallehin with Late Ayesi. He read Shawaqul Elhaam with late Shaykh Mujtaba Qazvini and attended late Allamah Mirza Mahdi Isfahani’s lessons on divine teachings. Meanwhile, he attended Kharij lectures by late Mirza Mahdi Ashtiani and late Mirza Hashim Qazvini (may Allah bless them).

In late 1368 A.H. he migrated to Qum to accomplish his studies in Fiqh and Usul. He was benefited by the two well-known scholars, Sayyid Hussan Tabatabaye and Grand Kuhkamari. The first gave lectures in Fiqh (Jurisprudence and Usoul (Fundamentals of Jurisprudence) and the second gave lectures in Fiqh only.

During his stay in Qum,he was corresponding with late Allamah Sayyid Bahbahani (the prominent scholar of Ahvaz province known as a follower of Hadi Tehrani’s school of thought). Their correspondence dealt with issues related to Qibla. He did not accept views maintained by Hadi Tehrani. Therefore,he corresponded with Sayyid Ali Bahbahani who appreciated his views and promised that he would see him from close on his visit to the holy shrine of Imam Reza (a.s.) in Mashhad. In early 1371 A.H. His Eminence left Qum for Najaf Ashraf and reached Karbala on the occasion of Arba`in (40th day) of Imam Husayn (a.s.). On having arrived in Najaf, he began attending Ayatullah Khu’i and Shaykh Husayn Hilli’s lectures in jurisprudence and fundamentals of jurisprudence for a considerably long time. Meanwhile, he attended lectures of other prominent scholars like Ayatollah Hakim and Ayatollah Shahryudi (may Allah bless them).

In 1380 A.H. Ayatullah Sistani traveled back to his hometown, the holy city of Mashhad, expecting to stay and settle in it. In the same year, he was awarded a permit by Imam Al-Khu’i and another by Shayk Hilli, certifying that he had attained the level of (ijtihad)- deduction of legal judgment in matters of religion. He was also awarded a diploma by the distinguished traditionalist and scholar Shakh Agha Buzurg Tehrani testifying to his skill in the science of “Rijal” biographies of ‘hadith’, prophetic traditions, narrators and that of ‘hadith’.

Upon returning to Najaf Ashraf in 1381, he embarked on research and teaching jurisprudence as expounded by the great jurist Shaikh al-Ansari in his book “al-Makasib”, He followed it with an exposition of al-Urwatul Wuthqa book by the jurist Sayyid Tabatabaye. He started giving lectures (externals) in fundamentals of jurisprudence in Sha’ban, 1384 A.H. He completed its 3rd course in 1411 A.H. (1990 A.D.). In 1418 A.H., he began teaching Kitab Al-E’tikaaf” after completing exposition on ‘Kitab Al-Sawm’ not so long ago. He is currently (Sha’baan 1423) teaching Kitab-ul-Zakat of Urwatul Wuthqa.
Some professors of Najaf Center for Theological Studies (Hawza of Najaf) were quoted as saying that they advised the late Ayatullah Khu’i to groom someone for the office of the supreme religious authority and the directorship of Najaf Seminary. Thus the choice fell on His Eminence, Grand Ayatullah Sistani for his merits, eligibility, knowledge, and impeccable character. Accordingly, he started leading the prayer in Imam al-Khu’i's mosque, al-Khadra at his life time in 1408 and continued leading prayers until the mosque was closed in 1414.

For the first time in 1384, His Eminence traveled to Makkah for pilgrimage. Then in 1405 and in 1406 he traveled to Makkah for pilgrimage for a second and third time consecutively. He started giving lectures (externals) in fundamentals of jurisprudence in Sha’ban, 1384 A.H. He completed its 3rd course in 1411 A.H. (1990 A.D.) His lectures in both the subjects have been recorded by some of his students.